Electron discharge apparatus



June 5, 1934. P. T. WEEKS ELECTRON DISCHARGE APPARATUS Original FiledSept. 17, 1928 J m F Patented June 5, 1934 UNITED STATES ELECTRONDISCHARGE APPARATUS Paul T. Weeks, Cambridge, Mass., assignor, by mesneassignments, to Raytheon Production Corporation, a corporation ofDelaware Application September 17, 1928, Serial No. 306,398 RenewedOctober 18, 1932 16 Claims. (Cl. Z50-27.5)

My invention relates to electron discharge apparatus and particularly tothe construction thereof. More specifically my invention relates to themanner of supporting the various electrodes of a vacuum tube.

It is highly desirable that the elements of a vacuum tube be rigidlysupported so that the electrodes are maintained in predeterminedrelationship under all conditions to which the tube may be subjected.Especially is this desirable in order that the so-called microphoniceffects may be avoided. Such effects are due to the relative position ofthe electrodes varying at an audible rate. By increasing the rigidity ofthe structure, it is obvious that the frequency of the elements will beincreased so that audible microphonic effects will be avoided.Furthermore, it is highly desirable that such a structure be simple,cheaply manufactured and assembled.

In general, the tube embodying my invention is characterized by a presswhich has sealing portions or wings in more than one vertical plane.

Standards are sealed in this press forming a rigid frame work. Tofurther increase the rigidity of the structure, the standards arepreferably substantially straight and parallel throughout their lengths,and at their free ends pierce an insulating member which retains them infixed relationship. The cathode, grid, and anode are supported withinthe space dened by the frame and insulating member. The anode ispreferably supported by two of the standards. In this way the anodestandards and insulating member contribute to form a rigid enclosingstructure for the grid and cathode. The grid and cathode each have oneend engaging the insulating member. The other end of one of theelectrodes is supported by a standard. The other end of the otherelectrode is supported by one or more wires sealed in the press,although it too may, if desired, be supported by another standard.

Referring to the drawing, Figure 1 is an elevation view of my inventionwith certain parts cut away.

Figure 2 is an elevation view at right angles to the view of Figure 1,showing certain parts in section.

Figure 3 is a View of the press.

Figure 4 is a view looking down on the tube with certain parts brokenaway.

Press 1 has portions or wings 2 in more than one vertical plane, and, asshown here, in two planes, preferably, though not necessarily at rightangles to each other. The top surfaces of portions or wings 2 arepreferably in one horizontal plane. Sealed in the outer parts of wings 2are standards or arbors 4, 5, 6y and 7 of metal, such as hard nickel.These standards are preferably parallel throughout their entire length,and as shown here, define the parallel edges of a solid geometricalfigure, in this instance, a rectangular prism.

By having the standards straight, it is possible to use hard, resilientmetals. Where, as in prior devices, the supporting standards had to bebent to meet the electrode surfaces, the use of spring metal waspractically impossible since the resiliency ofthe wire tended to make itstraighten out and difficult to work with. To avoid this difflculty,Wires of metal having little resiliency or else separate wires and weldswere used. In either case it is obvious that a weaker structure willresult.

The free ends of the standards pierce an insulating member 9, of anysuitable material, such as mica, lava or the like. This' insulatingmember 9 serves to rigidly connect orv anchor the free ends of thestandards to each other, and therefore may be termed an anchoringmember. This insulating member may be of any shape whatsoever, and isshown as substantially rectangular with the standards passing throughthe corners therei of. If desired, a symbol or the like may be stampedout in the mica. In order to maintain the insulating member on thestandards and prevent it from sliding down or coming off the standardsare preferably distorted as by crimping on both sides of said member.Any other suitable means for retaining the insulating member in place onthe standards may be used if desirable.

Supported by two of said standards is an anode or plate 11. This anodeis preferably made of metal gauze and so shaped as to provide a.substantiallyy cylindrical portion within it. The

anode may be made in two portions as shown in Figure 4, and slipped overstandards 4 and 6. All the standards, insulating member 9 and anode 11,mutually assist each other in forming a rigid structure within which theremaining electrodes may be supported.

Centrally disposed within the anode is a cathode structure, vhere shownas of the type adapted to be energized -by alternating current while atthe same time maintaining an equipotential electron emitting surface,although any desired kind of cathode may be used. The cathode structure,comprises a cylindrical metallic cathode 15, the outer surface of whichhas been suitably treated with chemicals so that, at an elevatedtemperature, a copious supply of electrons will be emitted. Engaging theends of cathode 15 lare insulating bushings 16 of suitable material, andthrough which pass leads 1'7 and 18, between which is connected alamentary heater 19 of platinum, tungsten or any other suitablematerial. The bushingscenter the leads and heater element and thusmaintain them out of contact with cathode 15. Small metal collars 20 maybe welded to the leads in order to maintain the bushings in place.

Lead 18 of the heater pierces insulating member 9 at the center to besupported thereby and has its end so connected as to be also supportedby standard 5 by means of Wire 22 suitably welded to both members. Lead17 of the heater is welded to wire 25 sealed in an intermediate portionof press 1. In order to provide a contact for the equipotential cathode15, lead 26 suitably welded to sleeve 15 is provided. This lead iswelded to a wire 28 sealed in an intermediate portion of press l. Thusit will be seen that the cathode structure is rigidly supported by wires25 and 28 at one end and insulating member 9 at the other end. Wire 22connecting standard 5 and lead 18 furnishes an additional support forthe cathode structure.

Between the cathode structure and anode is a grid comprising a helicalcoil of wire 30, the turns of which are maintained in xed relation toeach other by means of diametrically opposed Wires 31 and 32, suitablywelded or fastened to each turn of wire 30. One end of each of wires 31and 3 2 pierces insulating member 9, and as shown here,

is in a direct line between standards 5 and 7 and cathode lead 18. Theother end of wire 31 is bent and welded to standard 7 for support,as'wellas for conduction purposes. 1f desired, wire 32 may be omitted.

Suitable leads are connected to standards 4, 5, '7 and wires 25 and 28.The entire structure is suitably enclosed in a glass containing vesselwhich is exhausted and freed of all impurities in accordance with theusual practice. In order to clean up any remaining impurities and tomaintain a high vacuum, suitable chemicals such as magnesium may becarried by capsule welded to wire 51 and suitably supported from any oneof the standards. 'Ihe usual base is provided for quick detachableconnection of the various elements of the tube in a circuit.

A tube built as shown has been found to be free of microphonic effectsto an unusual degree. The frame comprising the standards when reinforcedby insulating member 9, provides an unusually rigid structure withinwhich the electrodes may be supported. Due to the rigidity of thestandards, the shape of the anode is maintained as desired.

As is well known, in ordinary tubes, trouble has been experienced by thefact that if the supporting wires for the anode tend to spring away fromeach other, the anode is usually pulled out of shape and has its wallsbrought undesirably close to the grid making a connection between saidelectrodes possible. On the other hand, if the wires tend to approacheach other, the anode is bulged ards in xed relationship tol each other,irrespective of any tendency to spring away.

The insulating members are punched out by Aquently to be seriouslydamaged in transportapredetermined relationship,

machine and hence are uniform. l'I'he standards are automaticallymaintained in place prior to sealing. The frame as a whole willtherefore be the same in all tubes within close limits. This means thatthe three electrodes at the top will always be in xed predeterminedrelationship and be independent of human hands. Wires 25 and 28 are alsomaintained automatically before sealing and are bent by automatic means.When lead 17 of the cathode heater is welded to 25, the cathodestructure is correctly positioned. Grid wire 3l is also bent so thatwhen its end is welded to standard 5, the bottom of the grid iscorrectly positioned. In this way, tubes may be so accurately built thatthey will have substantially similar constants and properties. j

Since the grid is supported between one of thc standards and theinsulating member, -it is evident that any vibration of the gridrelative to the plate is practically impossible. The mutual rigidity ofthe standards and insulating member is such that the grid is rigidlysupported. The cathode structure being supported by two wires .V at thebottom and the insulating member, as well as the connecting wire to oneof the standards, is rigidly maintained. Unlike tubes of the prior art,no amount ofordinary shaking or vibration, either intentional orotherwise will substantially adect the relation of the electrodes toeach other Vor to the press. The tube disclosed here is not top heavyand does not have such an unsupported length of wire, straight orcurved, as to make it structurally weak. Tubes as disclosed by prior arthave been known fre-v tion or handling violently. A tube built as dis.

closed here has been found to'be so strong me. chanically that anydamage to the tube is practically impossible without the breakage of thecontainer.

1. In a vacuum tube, a. press, a plurality of standards sealed in saidpress, said standards being parallel for their entire length andlying inmore than one plane and an insulating member at the free end of saidstandards maintaining said standards in spaced relationship.

2. In a vacuum tube, a press, a plurality4 of standards having wingsextending in a plurality of planes lying in a plurality of planes sealedtherein, an insulating member directly engaging and retaining the freeends of said standards in an electrode and means for supporting one endof said electrode in said insulating member and the other end of saidelectrode on one of said standards.

3. In a vacuum tube, a press having wings extending in a plurality ofplanes, a plurality of straight standards sealed therein and lying inmore than one plane, an insulating member retaining the free ends ofsaid standards in iixed relationship, an anode, grid,` and cathode, oneoi the ends respectively of said cathode and grid engaging saidinsulating member and means for maintaining the other ends of saidcathode and grid in iixed relationship.

4. In a vacuum tube, a press, a plurality of standards sealed therein atpoints the outer ones of which form corners of a polygon transverse tothe direction of the standards, an insulating member engaging the freeends of all said standards, an electrode comprising a helical member anda wire member engaging and retaining the coils of the helix in place,and means for retaining an end of said wire member in said insulatingasv member and the other end on one o! said standards.

5. In a vacuum tube, a press having wings extending in more than oneplane, a plurality of standards lying in more than one plane sealedtherein, an insulating member, the free ends of said standards engagingsaid insulating member, an anode, grid, and cathode, said anode beingconnected to and supported on two of said standards, said grid beingconnected to and supported by said insulating member and a thirdstandard said cathode being engaged and supported by said insulatingmember.

6. In a vacuum tube, a press having wings ex- .ending in more than oneplane, rectangularly disposed straight standards sealed therein, aninsulating member. directly engaging said standards, an anode, grid, andcathode, two of said electrodes directly engaging said insulatingmember, and the remaining electrode being supported by at least one ofsaid standards.

'7. In a vacuum tube, a press having wings in at least two planes,straight standards lying in a plurality of planes sealed therein, aninsulating member engaging the tops of all of said standards, andelectrodes mounted on said standards and below said member.

8. A space discharge device comprising a discharge vessel, an electrodesupporting press having a plurality of wings extending in more than oneplane in said vessel, four straight standards sealed in said wings, thesealing points of said standards forming corners of a quadrangle, arigid member directly engaging and mechanically connecting said fourstandards thereby forming a rigid assembly, an anode engaging two ofsaid standards diagonally disposed toward each other, a grid engaging athird standard and said rigid member, a cathode engaging said member andmeans extending from said press for additionally supporting saidcathode.

9. In a space discharge device, a press having wings extending in morethan one plane, four straight standards sealed in said press, thesealing points of said standards forming corners of a quadrangle, aninsulating member directly engaged by the free ends of said standards,an anode engaging two of said standards diametrically disposed, a grid,said grid being supported by said insulating member and on a thirdstandard, and a cathode, said cathode being supported by said insulatingmember and means extending from said press for additionally supportingsaid. cathode.

10. A space Adischarge tube comprising a discharge vessel, an electrodesupporting stem in said vessel, more than two upstanding wire standardsanchored to said stem, the anchoring points of said standards formingcorners of a polygon transverse to the direction of the standards, ananchoring member directly engaging more than two of said standards lyingin more than one` l 3 plane at a distance above said anchoring pointsand joining said standards into a rigid structure. and electrodessupported at a plurality of points on said structure.

11. A space discharge tube comprising a discharge vessel, an electrodesupporting stem in said vessel, more than two upstanding wire standardsanchored to said stem, the anchoring points of said standards formingcorners of a polygon' transverse to the direction of the standards, ananchoring member directly engaging more than two of said standards lyingin more than one plane at a distance above said anchoring points andjoining said standards into a rigid structure, and a plurality ofelectrodes supported on said structure insulated from each other.

12. A space discharge tube comprising a discharge vessel, an electrodesupporting press having a plurality of Wings extending in more than oneplane in said vessel, more than twoupstanding wire standards sealed intosaid wings, the sealing points of said standards forming corners of apolygon transverse to the direction of the standards, an anchoringmember directly engaging the upper ends of more than two of saidstandards lying in more than one plane, a plurality of electrodessupported on said structure insulated from each other below saidanchoring member, more than one of said electrodes being each supportedat one end by one of said standards and at the other end by saidanchoringl member.

13. In a space discharge device, a press having wings in more than oneplane, a pluralityy of standards sealed therein, a plurality ofelectrodes supported on said standards, and an insulating memberdirectly engaged by the free ends of said standards, the points ofengagement between said standards and insulating member dening athree-dimensional geometrical gure.

14. In a space discharge device, a press having wings extending in morethan one plane, polygonally disposed straight standards sealed therein,an insulating member having its corners engaged by said standards and acathode engaging an intermediate portion of said member, and a plu-Irality of electrodes supported on said standards.

l5. In a space discharge device, a press having wings in more than oneplane, straight standards i lying in a plurality of planes sealed insaid wings and an insulating member whose main plane is substantiallyperpendicular to the axis of the press, engaging at least three of saidstandards lying in at least two diierent planes, anda plurality ofelectrodes supported by said standards.

16. In a space discharge device, a press having wings in at least twoplanes, straight standards sealed therein in a plurality of planes, andan insulating member directly engaged by said standards, and a pluralityof electrodes supported by said standards.

PAUL T. WEEKS.

CERTIFICATE oF CORRECTION.

.mem No. 1,961,269. p l Innes, .1934.

PAUL T. WEEKS.

It is hereby certified( that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,lines 117, 123, 132, 142, and page 3, lines 3, 14, and 22, claims l, 2,3, 4, 5, 6, and 7, respectively, for "vacuum tube" read space dischargedevice; page 2, lines 123 and,124, claim 2, strike Aout the words "aplurality of standards" and insert the same before "lying" in line 125.of same claim; line 135, claim Inafter "member" insertA directlyengaging and; and line 143, claim 4, after "points" insert a comma; andthat the said Letters Patent should be read with' thesecorrectionstherein that the same may conform to the record of the ease in thePatent Office.

Signed and sealed this 24th day of July, A. D. 1934.

llryan M. Battey f (Seal) l i Acting Commissioner 0f Patents.

